title: Phospho-proteomic analysis of mantle cell lymphoma cells suggests a pro-survival role of B-cell receptor signaling.
abstract: BACKGROUND
  Mantle cell lymphoma (MCL) is currently an incurable entity, and new therapeutic approaches are needed. We have applied a high-throughput phospho-proteomic technique to MCL cell lines to identify activated pathways and we have then validated our data in both cell lines and tumor tissues.
  
  
  METHODS
  PhosphoScan analysis was performed on MCL cell lines. Results were validated by flow cytometry and western blotting. Functional validation was performed by blocking the most active pathway in MCL cell lines.
  
  
  RESULTS
  PhosphoScan identified more than 300 tyrosine-phosporylated proteins, among which many protein kinases. The most abundant peptides belonged to proteins connected with B-cell receptor (BCR) signaling. Active BCR signaling was demonstrated by flow cytometry in MCL cells and by western blotting in MCL tumor tissues. Blocking BCR signaling by Syk inhibitor piceatannol induced dose/time-dependent apoptosis in MCL cell lines, as well as several modifications in the phosphorylation status of BCR pathway members and a collapse of cyclin D1 protein levels.
  
  
  CONCLUSIONS
  Our data support a pro-survival role of BCR signaling in MCL and suggest that this pathway might be a candidate for therapy. Our findings also suggest that Syk activation patterns might be different in MCL compared to other lymphoma subtypes.
authors.affiliation: Department of Pathology and Diagnostics, University of Verona, P.le Scuro 10, 37134, Verona, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Pighi
authors.forename: Ting-Lei
authors.initials: TL
authors.lastname: Gu
authors.forename: Irene
authors.initials: I
authors.lastname: Dalai
authors.forename: Stefano
authors.initials: S
authors.lastname: Barbi
authors.forename: Claudia
authors.initials: C
authors.lastname: Parolini
authors.forename: Anna
authors.initials: A
authors.lastname: Bertolaso
authors.forename: Serena
authors.initials: S
authors.lastname: Pedron
authors.forename: Alice
authors.initials: A
authors.lastname: Parisi
authors.forename: Jianmin
authors.initials: J
authors.lastname: Ren
authors.forename: Daniela
authors.initials: D
authors.lastname: Cecconi
authors.forename: Marco
authors.initials: M
authors.lastname: Chilosi
authors.forename: Fabio
authors.initials: F
authors.lastname: Menestrina
authors.forename: Alberto
authors.initials: A
authors.lastname: Zamò
mesh_terms: D015153:Blotting, Western; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D004789:Enzyme Activation / Q000187:drug effects; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D020522:Lymphoma, Mantle-Cell / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008954:Models, Biological; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D040901:Proteomics / Q000379:methods*; D020794:Receptor Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D011947:Receptors, Antigen, B-Cell / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013267:Stilbenes / Q000494:pharmacology; D014443:Tyrosine / Q000378:metabolism
chemical_list: D007527:Isoenzymes; D010750:Phosphoproteins; D011947:Receptors, Antigen, B-Cell; D013267:Stilbenes; D014443:Tyrosine; C041525:3,3',4,5'-tetrahydroxystilbene; D020794:Receptor Protein-Tyrosine Kinases; C084944:TYRO3 protein, human